If you try to burn the last remaining page of the Mysterium Xarxes, it turns into a bucket!
This is because all Skyrim items are first loaded into the database with their base image as a bucket. They are changed individually based on what the item and item class is supposed to be. However, the last remaining page of the Mysterium Xarxes, here located at the Dawnstar Museum of Dagon, has no burned version of itself in the database. So if you alter it with fire, it becomes a bucket again.